1. Field of Industrial Applicability
This invention relates to a device for controlling the feed speed of parts and is suitable for use in handling projection bolts or stud bolts.
2. Prior Art
In device of the type in which parts holding means are installed at the end of the feed passage, parts are fed to the parts holding means via a parts feeding tube by utilizing compressed air.
According to the prior art described above, parts cannot reach the parts holding means unless the parts are started from a parts feeder at a considerably high speed. Therefore, in the case of parts holding means which is provided with a surface for supporting the welding projections of projection bolts, a number of dents are formed in the surface, interfering with the smooth slide of parts. Further, since the parts holding means of a stud welding machine is of the type having a plate spring for holding a part, the speed of a part moving to the plate spring must be within a predetermined allowable range. If not, there is a problem that such part slips through the plate spring or is unable to spread the plate spring. Further, if the parts feeding tube extending from the parts feeder to the parts holding means is long-sized, transport of parts one by one takes much time, a fact which is undesirable for improving productivity.